Estudo da Fauna de Invertebrados Presentes na Serrapilheira do Solo em uma Floresta de Terra Firme na Flona de Caxiuanã, Melgaço, Pará

Abstract

The contribution of soil invertebrates in the process of A. decomposition is mainly linked to the physical breakdown of plant tissues, of small dead animals and to the provision of fecal material, making organic matter available. The present work aims to estimate the composition and abundance of soil macrofauna, identifying and comparing these patterns in the periods before and after the Esecaflor experiment, which simulates the effect of "el nino" in the forest area of the Caxiuanã National Forest and in areas of the Multitaxonomic Inventory of Caxiuanã project, which make up a gradient of soil moisture, in order to establish the dynamics of these variations in relation to moisture gradients from flooded soil to a soil 80% drier, by experimental intervention. The study of variations in macrofauna composition, in a situation of water stress in the environment, can provide important elements for the understanding of the mechanisms involved in this process. The individuals were collected in pitfall traps, within the Caxiuanã National Forest, from the control and experimental plots and the four plots of the IMC project and kept in 70% alcohol in the laboratory. The highest abundance occurred in the Station plot (27%), followed by the Control (18%), Puraquequara (18%), Experimental (14%), Curuazinho (13%) and Caiçara (10%) plots. Phoridae was the most abundant family with 37% of the individuals, with 27%, 21% and 15%, respectively for Drosophilidae, Cecidomyiidae and Sciaridae. Although there is some difference in the abundance of individuals, the hypothesis of a difference between the environments can only be accepted at a 10% significance level, so that little can be inferred about the behavior of the dipteran families in question, because within these there are groups that respond differently to the degree of humidity between the plots. Possibly a more detailed study to identify the species of these families of Diptera will be able to more satisfactorily infer on how the environment influences the composition and abundance of the macrofauna under study.